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7 votes
2 answers
613 views

Fractional Brownian motion of Riemann-Liouville type is not a semimartingale

Given a filtered probability space $(\Omega,\mathcal{F},\mathbb{F},\mathbb{P})$ satisfying the usual conditions, $B$ a standard one-dimensional Brownian motion and $H\in(0,1/2)$. Consider the process $...
El_mago's user avatar
  • 199
3 votes
1 answer
1k views

Strong solution for geometric brownian motion with varying drift and volatility

I have an equation of the form: $$dX_{t}=\mu(X_{t})X_{t}dt+\sigma(X_{t})X_tdZ_{t}$$ I know that if I wrote it as $dX_{t}=\mu(X_{t})dt+\sigma(X_{t})dZ_{t}$, I would need strong assumptions on the ...
Pcw.'s user avatar
  • 315
2 votes
1 answer
596 views

Question about the exit time of a time-homogeneous Itô diffusion

Consider a one-dimensional Itô diffusion: $$\mathrm{d} X_{t}=b\left(X_{t}\right) \mathrm{d} t+\sigma\left(X_{t}\right) \mathrm{d} B_{t}$$ where $X_0 = 0$ and $B_t$ is the standard Brownian Motion. ...
香结丁's user avatar
  • 331
1 vote
1 answer
460 views

Reflected SDE with non-Lipschitz coefficients

I have an equation of the form: $$dX_t=\mu(X_t)dt+\sigma(X_t)dZ_t+dL_t, \quad X_0=x_0\in (-\infty,a]$$ where, $L_t$ is the reflection function (as in Skorokhod, 1961). This reflection does not allow ...
Pcw.'s user avatar
  • 315
1 vote
0 answers
89 views

Comparison of the numbers of particles surviving forever

Consider two $N\text{-}$particle systems as follows : for $1\le i\le N$, $$X^i_t=1+\int_0^t(b+\phi^i_s) \, ds+W^i_t \quad\mbox{and} \quad Y^i_t=1+ct+W^i_t,\quad \forall t\ge 0,$$ where $c>b>0$ ...
GJC20's user avatar
  • 1,334